okay, gang. let's begin.

we were talking about radiation, heat transfer by radiation. we've got heat transfer by conduction, heat transfer by convection and, last of all, heat transfer by radiation. and heat transfer by radiation, we talked about this idea. that everything is emitting radiation of some frequency. these are electromagnetic waves. we'll be talking about electromagnetic waves later in the course. and electromagnetic waves have a frequency. there's a high frequency. tick, tick, tick, tick, tick, tick, tick. and there's a low frequency. tick, tick, tick, tick. there's a vibrational frequency to waves. and that vibrational frequency to the waves is directly proportional to the temperature. temperature of the sun is enormous, and therefore we have an enormous frequency, so high a frequency that it activates the optical system in your eyes, we call it light. that's very, very high frequency. millions of billions of cycles per second of such little vibrations. very, very high frequency. high frequency because the sun's electrons are shaking at high rates.

we'll gonna learn later on, if you take an electron and shake it back and forth, you'll get a wave in space that will shake back and forth at the very same frequency. so it stands for a reason, something of a high temperature with a lot of molecular motion, okay, a lot of charges moving, moving, moving, that that high temperature would give you a high frequency. so this is not counterintuitive. sometimes, we learn things that are kinda a little bit against common sense. we have to look a little deeper till we find out, "hey, it fits after all." this one, we don't. it makes sense that a high temperature would emit a high frequency. if you take a piece of metal, you guys can all see this. you're seeing this piece of metal because light is being reflected from the metal and go to your eyes. but if i turned all the lights out, you wouldn't be able to see this metal. but what i could do is i could start to heat it, maybe i could pass an electric current through it. and i could heat it, heat it, heat it, and pretty soon it would start to glow. and what color will the glow first, gang? red. it will turn red, and then kinda red orange, yellow, and then it will smear out to a white. it will become white hot.

and that would-- and that means what? the temperature is high, high enough so the radiation it's emitting can be seen. see, this is emitting radiation right now. but the temperature is so slow, the temperature of iron is so low compared to that for incandescent, it's over a thousand degrees. the temperature of iron is so low that the radiation that's coming out doesn't activate your sense of sight at all. what you're seeing is reflected light from these hot lamps above but not the light coming from here. but everything is emitting radiation. question? how fast does this radiation travel? all this radiation travels at 300,000 kilometers per second. that's the speed of light. we know light travels that fast. it turns out that the heat rays, so called heat rays, all electromagnetic radiation, 186,000 miles per second or 300,000 kilometers per second, speed of light. and that's how fast these radiations travel. everything is emitting, and everything is absorbing. if something absorbs, all it kept catches, then it reflects none.

i'll show you an idea right here. there's a hole there. is this hole absorbing the radiation that hits it or is it emitting? it absorbs. i've got the color-- i've got the inside of this box painted, gang. and guess what color it's painted? white. black. what color does it look like now? black. white. you've been reading the book, right? [laughter] and we find out, lo and behold, it's white inside. isn't that nice? okay. but when i close the box, boom. look into your neighbor's eyes right in the very, very center, do that right now. how many are shy? [laughter] they said, "no, i don't want to look in the eye." come on, right in the eye. come on. right in the middle. right in the middle. how many are going like this? haah. that's nice, isn't it? isn't that nice? hey, how come the center of the eye is black? there's no reason for that. everyone got black pupils. why black pupils?

because they absorb. because they're like this. they're absorbing. they're absorbing. how much light that goes into your eye that are bouncing around. how much do you think goes back out again? how much light that comes in here and they'll go through all these multiple reflections comes back out the hole? not very much. so the hole to you looks black. okay? because there's what-- this is a net absorber. however, if i put fire in here, made it very, very bright, then you'll see that hole very, very bright, then it would be a net emitter. we call this a black body. a body that absorbs all the radiation that hits it appears black to the eye. we call that a black body. there's a whole science of black body radiation. we won't be getting into that. we talked about this temperature up here. how about like this with-- this is to say if frequency is directly proportional to temperature, then if you double the temperature, what would happen to the frequency of radiation? double. that's what it means when you write two things like these with a proportion. see, there're no square or cube or anything like that.

that means one is proportional to the other. we've got that idea a long time ago, yeah? okay. this is double the temperature, double the frequency. well, let's suppose i consider something that's one degree celsius. if something is one degree above freezing, would it be radiating energy? yes. would that energy have a frequency? how about i compare that to radiating at two degrees above celsius? would that be radiating energy? would that energy have a frequency? yes. would that frequency be doubled? no. check your neighbor. yeah. ah. hey, gang. would the temperature be-- would the frequency be doubled? get right to that point. get right to that question. the question is: wouldn't that work best for kelvin? yeah. honey, it will only work for kelvin because one degree celsius is not twice as hot as two is--

i should say two degrees celsius is not twice as hot as one degree celsius. see, to say twice as hot is to imply twice the internal energy. try this one. the waitress brings over some coffee because you've ordered coffee with your apple pie, and you say, "oh, i'd like the coffee really hot." and she brings it over, and you put your trusty thermometer in, and, son of a gun, it's iced coffee. ice cubes and everything. it's zero degrees celsius. and you say to the waitress, "no, i know you're busy and all, "but could you give me some coffee that's hotter than this?" she says, "how hot do you want it?" i said, "well, i'd like to drink it twice as hot." what's the temperature of the twice-as-hot coffee if it's zero celsius to begin with? okay, gang. in this case, i think you see that the celsius scale doesn't work. no. because twice as hot is zero degrees. zero degrees, there's still energy there, yeah? there's a lot of internal energy. and to say you have twice the internal energy, hey, two times zero is what?

it turns out two times zero is 273. 273. let's be talking about that. we haven't talked about the kelvin scale yet. we talked about the scales we talked about. we talked about the fahrenheit scale, fahrenheit degrees. we went from 32 to 212 for the temperature of boiling water and the temperature of melting ice. and we talked about zero degrees and 100 degrees, and this was the celsius temperature or centigrade, celsius centigrade, same, same, okay? and--but now, we have to talk about the absolute zero of temperature when you start to take ratios of temperatures because this is not the coldest that one can get. you can get a lot colder than that. that liquid nitrogen we had in here the other day that was about-- almost 190 degrees below this. how far down can you go? and it turns out how far down you can go is 273 degrees down here.

and down here on the floor, that is the absolute zero, down there. that's the absolute zero temperature. so it turns out on this kelvin scale, we don't even say kelvin degrees. we just say kelvins. i mean, kelvin was really honcho, okay? these are all kelvins, all right? on this kelvin scale, the point at which ice melts would be 273 positive. see, with the kelvin scale, there's no negative numbers. everything is positive. ain't that nice? see? and then the temperature of boiling water is 373 because they have made the kelvin scale, the scientist-types, so that it has the same divisions as the celsius scale. but absolute zero is 273 degrees under there. so if we have that ice coffee that's, say-- let's take something that won't change state because it turns out the ice coffee, something will happen to it when it gets up to 100 degrees celsius. what will it do? boil. it will start to turn into steam, see.

but let's suppose you had like a piece metal. i have this metal here at zero degrees. and i make it twice as hot, twice the internal energy. see if your neighbor knows what would the temperature be in celsius of this piece of iron bar twice as hot as zero degrees. check your neighbor. okay, gang. what's the answer? 273. 273 degrees celsius. does everyone see that? if you don't see that, i think you can see it with this little story. let's consider celsius the village tailor. and celsius is a tailor who has a shop. he makes gowns for graduations. and he has a shop, and he has a ruler here, okay? and his ruler is right against the wall. now, does that ruler have to have readings that go all the way down to the floor? no. it turns out it doesn't because the shortest customer that tailor is gonna have is probably about this high. and the tallest customer is probably about this high.

so celsius only need to put a sort of measuring device from here to here. there's no need to go way down there, not for measuring the height of adults, people who graduate, yeah? so we start here. all right, it turns out by the way that from here to the floor is 273 notches down, okay? okay. now, one day someone comes in to the store, and they get measured, and son of a gun, there's a little tiny guy like this and still-- measures the height. he says, "my gosh, you're right at the zero mark. you're really, really short, aren't you?" and the dude says, "i got a sister twice as tall as me." how many notches tall is the sister? do you see? you would see that here we got zero on the scale, twice zero is not zero. the sister must be up to here. 273 notches higher, do you see that? so we gotta talk about self-- i mean, no, kelvins, kelvins. whenever you're talking about something like this, nature's temperature.

see, celsius degrees and fahrenheit degrees are also people's temperatures. a nature's temperature doesn't start with a melting point of ice. nature's temperature starts at the lowest possible temperature you can get to. you know, we talked about the energy of motion of molecules high at absolute zero. none. no more to give up. things there at the rock bottom, that's the lowest temperature you can get. and so we always talk about things like this in terms of nature's temperature, kelvins. some people in chemistry classes say, "how come we gotta convert to kelvin all the time?" well, if you've taken differences in temperature, you don't have to. but if you're taking ratios, you have to take nature's temperature, kelvin degrees. another, do you think kinda neat thing that is another common sense idea is newton's law of cooling? this one makes sense. it has to do with the rate.

the rate of cooling is proportional to delta t. in this case, i wouldn't have to be concerned with kelvins because the difference in temperature from here to here and the difference from here to here would be the same. do you see? i'm not taking a ratio. but over here at newton's law of cooling is-- for the rate of cooling is proportional to the difference in-- now what do you mean difference? you know, delta means difference. that means how hot something is compared to what the surroundings are. if this thing here is red hot, and this is maybe something like of 500 degrees above the surroundings, then that's a high delta t. guess what the rate at which this degrees are gonna clip off will be, high rate. see? if i take this thing and warm it up a little bit like this. now, it's a little bit warmer than the environment. how quickly does it cool? not very quickly because delta t is very small.

if i put this in an oven and turn it red hot, take it outside. [makes sounds] this thing starts cooling like mad, okay? i mean, let's suppose every-- by you hear click, click, click, okay? red hot, click, click, click, click, click, click, click, click, click, click, click, click, click, see? one hot, click, click, make sense? it makes sense doesn't it? very, very--things that very, very hot compared to surrounding will cool out quickly. things that aren't so hot don't cool up so quickly, huh? so that's kinda make sense. if you got a can of beer or something, you wanna cool it down quickly. you put it in a fridge, someone says, "no, no. put it in a freezer, it'll cool faster." you say, "well, honey, if it gets down "to what the fridge is that's good enough. i'll just leave it in a fridge." who's right? put it in a fridge or the freezer, you wanna cool it faster. how many say same-same? if you wait five minutes it's the same. check your neighbor. you kinda see that, gang? you kinda see that?

in places where it's cold in the winter, when do those homes leak energy more, on a cold day or a warmish day? on a cold day, there's a greater delta t between the temperature inside the home and outside. and a great big delta t means, honey, you are gonna have a high rate of cooling. and you know what you pay for when you hit your home? what you pay for really ultimately is the heat that's leaking out all of the time. otherwise, you heat your home up in september, keep your doors all closed, you wouldn't have to burn any more fuel for the rest of the winter. but that's not true, the heat's leaking all the time mostly through your windows. and the greater the delta t, the greater the difference in temperature between inside and outside, then the greater it's gonna be the rate of heat flow. and opposite's true, too, if you're in a climate like around here. we are air conditioning all the time. the greater the difference in temperature between the outside and the inside, the greater the heat flows from the outside into your home making your air conditioning bill goes up higher. so the greater the delta t, the greater the rate of cooling

or warming if you put it in the other way. they kinda make sense, doesn't it? so that's the common sense type thing. this delta t is interesting. if you have small delta t, small changes in temperature, it turns out--i heard this some years ago. if you have a frog, a frog cannot discern small changes in temperature. if you put a frog in a pan of water, and then put that water on a hot plate. turn the hot plate on. and heat the water up very, very slowly. the frog will not discern the small temperature changes. and the frog, i heard, will just sit there and boil alive. i heard that, being the science type, i had to try it. [laughter] so it's in ecology, went up to the biology lab, third floor, i picked out a frog, "hi, harry." and i put that frog in a little pan, okay?

so ain't that frog and so-- up there anyway. that frog was gonna get right up in the head, anyway, okay? i put the--and i made a deal with the frog. "froggy, if you survive this, i'll put you outside "with the seagulls. i mean, i'll put you outside for freedom, all right?" and i put the frog in there, and i put him in the hot plate and i watch, i watch, i watch and suddenly, i know it was true. that frog was free to jump in any time. and the frog stayed there, because delta t was very small, small, small. that heat up very, very quickly, the frog will sense it and jump, but the frog got used to it. and then i heard this is not restricted to frogs. guess what else behave the same way begin with p and with eople. peoples, yeah. people are the same way. you, guys, know that? if you get in a tub and someone heats it grad-- this happened in noe valley, in noe valley in california a few years ago. a couple are sitting in their hot tub, and they had a faulty heater. and the heater kept heating and heating and heating

and the people just kinda get drowsy, get drowsy and stayed right in there and cooked alive. oh, i mean cooked dead, okay? yeah, people the same way. as long as you make delta t small, small, small, small, small, you'll get used to it. you'll feel no pain, and you're just kinda check out. this has an interesting application. that you can reverse to-- say again. that you can everse to-- i think it's the same thing as with colder too. if you get gradually, gradually, gradually, you will accept it. you will become used to it people are like that. we become used to all sorts of adversity if it's given to us n small enough doses. like the name--you want, like sound and effect. and you could walk into a friend's factory and go in there and say, "my god, how could-- it's so noisy. how can you stand it in here?" he say, "oh, i get used to it. "when i came here, there was two machines going "and then three and then four and then five and you kinda get used to it." 'cause they can't hear anymore, okay, that type of thing, yeah.

really, you'll get used to that. now, i had friend from japan, for example, come over to see me in san francisco and he saw all the bars on the windows. "what are all these bars for?" i said, "that's to keep the thieves out." he say, "you guys are living with--you got the bars on the wrong side-- bars are on the thieves." "oh, no, no. the thieves have their rights, man, you know?" and other thing is we get so used to it, so used to it. first, the bar on this one as ain't before, you know, the whole city is a barricade, you know? something that happens slowly, slowly, slowly, you get used to and you accept. it's like the nuclear missiles, right? first a few, right? then a few more, then a few more gradually they-- living in a whole world ready to blow up and well, you kinda get used to it. [laughter] small enough doses. something happens in san francisco at fisherman's wharf all the time that kinda bothers me. it's like auschwitz there. auschwitz. you get down there you wanna get your crabs, you wanna get your lobsters or you go to fisherman's wharf and you wanna order a nice lobster dinner.

now how do you-- what do you think that-- with that lobster you're eating, what do you suppose-- the fate of that lobster is before you eat it? they come out and say, "hey, do you want this one here?" and this old charlie go like this, you know, "hey, hey, not me, not me." [laughter] and take you on your charlie's. what do they do to that lobster? boiled. they boil that lobster. now, is there any concern for the lobster's well being? no. you want that lobster right away, right? you want it quick 'cause you got things to do. you know what they do? they take that lobster, open up a big pot, a boiling water that's boiling, boiling and they throw the lobster in. let me ask you a question, what do you suppose the lobster thinks about that? [laughter] what happen to that lobster-- [makes sounds] the lobster freaks. so you get your lobster, your lobster come to eat, right? and you looked down your lobster, which your lobster-- [makes sounds] and you're eating a lobster looks like that? why do they do that?

why not--and i'm serious, why not take the lobster and put it in water that's room temperature, "hi, charlie. bye, charlie." no pain. then put the lobster on a stove. last time, i--that's the way i cook lobsters, i do it that way. you put the lobster on the stove. room temperature water. then turn on the heat-- [makes sounds] --bring it to a boil, your lobster's cooking, your lobster, your lobster's-- [laughter] --a lot better. you're eating a happy lobster. i'm telling you, yeah. i don't understand that. i don't understand that. why freak out the lobster like that. what if there's a lobster heaven and you go, "oh, what did you do to my kinfolk." yeah. so cook your lobster on room temperature water and bring it gradually to boil. a lobster won't feel a thing. they'd be okay. eat a happy lobsters. lee, did you have a question?

in cases like this, wouldn't it be wiser to kind of check your environment every once in a while just to make sure that you're right? or maybe death or something like if you're in hot tub or anything. it's always good to check your environment to see what the delta t is. and the delta t could stand for so many things. true? yeah. hey, here's an easy question to answer, gang. no, no. here's an easy question not so easy to answer. little kid says to you, "so you live in hawaii. really nice, nice and warm all the time." "yup, nice and warm all the time, man." "i got some friends live up in northern alaska. it's cold all the time." "well, that's the way alaska is, man." [laughter] "how come it's so cold up there and so warm in hawaii?" then you say, "well, there's no reason for that. "hawaii is tropical and alaska is not. that's it." the kid says, "no, back in the question, why?" and you say...

why is it so warm here and so cold up near the poles? is there a reason for such a thing? check the neighbor. well, that's easy enough. hawaii is closer to the sun. alaska is farther away. is it true? is hawaii closer to the sun than alaska? you guys know that the closer and closer you get to the sun, the hotter it is? you know that? you know you get within a million miles of sun, the best materials you can make with vaporize-- not vaporize the term real hot, well, maybe vaporize. you guys been knowing that? unless you go at night time? [laughter] well, how about that? it is true that hawaii is closer to the sun than alaska? yes or no? - yes. - that's right. yes, that's true. is it the reason?

- no. - no, it's not the reason. let's take a look and see if we can see why. here's the earth, sunlight. the sun is way, way up there. sunrays coming in. they fan out a little bit, okay? but essentially, they're parallel. they're coming in. okay. now, here the sunrays, here's hawaii down in here and there's alaska up there. now, hawaii is closer to the sun. but that's not the reason, gang, is it? because let's suppose i take something like this eraser and i put the eraser here, boom, let's draw it in here. so many acres of land. now, let's consider the same acreage up north. see the reason already? can you see the reason already?

even if you don't have the words, can you say, "hey, yeah. "over here, you'd catch more energy "than you would here, more energy per area here than here." this is one of those things that really makes sense, doesn't it? right? in fact, you can count them up. what do we got? 1, 2, 3, 4, yeah? and now here we got what? one, maybe two? so your energy is more concentrated here. over here, it's more spread out, the same energy over more area. so over here, it's gonna be cold and cooler climate, over here, what--hotter climate. it gotta make sense, doesn't it? that also tells us about the seasons too. you know, it turns out, around here in hawaii, you don't know too much about seasons. but let's talk about it anyway. sun. earth.

earth six months later. it turns out the earth-- see how we have it here? the earth is tipped. this is the polar axis going through here. so the earth is tipped, okay? so that tip is about 23 1/2 degrees. that tip remains constant all around the sun. so over here--just like that, about 23 1/2 degree tipped like this. okay. and six months later, the tip is the same. it has the same angle when i'm here as over here, rotating about the same axis. that's our daily axis. every day, how long does it take for this to turn in one time? one time. one time, one time per day. we know that, right? so--but these are six months apart. here's the equator. the equator. there's the sun. this is not the scale. but i'm gonna label one of these, june or december?

if one is june, so the other is december. and you guys, look and see which one he gonna put down june and which one he gonna put down december. check with the neighbor and see what neighbor say. okay, gang, what did you pick? how many say this should december? how many say this should be june? yehey, the whole class. all right. you'd be knowing these things. see? this is gonna be june, right? because what happens in june? we're down in here. look who's catching more energy, huh? what happens six months later? well, take a place that's up a little higher about like san francisco or denver, colorado or oklahoma city, somewhere like that in the mainland, yeah? let's look over here. there down in the summer time, they're getting the energy pretty flushed in, yeah? six months later, over here. all right. now, here they are. but now it's nighttime.

this part is a nighttime, isn't it? not here around the day. but look over here. oh, they're only catching a little bit. people down here in buenos aires, they are the ones collecting all the energy, south america. that's why these-- the countries down below, south america and australia, in december, would be having their summers, yeah? and we have ours just the opposite. it kind of makes sense, doesn't it? yes. look at the globe. do you see? look at-- in the summertime, there's the tip toward you, huh? now, here's-- it says the old sun right here. everything i can see-- you guys can't get back and you'll see this. but i can see amsterdam right there. all right? now, amsterdam, that's halfway mark. amsterdam is right in the sun, okay? so it's day, day, day, day, day, day, day, day, day, day, day, day, day, day, day, day. sun down. night, night, night, night, night. sun up. day, day, day, day. [laughter]

- get the idea? - yeah. so they're in the daylight most of the turn. how about at a place that's on the daylight all of the turn that's just barely on that? of course, the north pole is. so when at north pole, daylight is 24 hours a day. but you come down to a certain point where it just comes up-- in fact, i can see it right here. it's up here. and that point is called-- anyone know? where? right there? you guys don't know about it? it's too frigid. it's a circle. beginning with an "a". arctic circle. arctic, that's the arctic circle. the arctic circle is the point where you can get day for 24 hours a day on june 21st, okay, june 21st. and other one is where you get nighttime 24 hours a day. because what happens when the sun's on this side, okay? and here's where you get your long, long winter nights. night, night, night, night, night, night, night, night and a very, very short day. so in the wintertime, very short days up-- the higher you go toward the north pole.

my brother lives in costa rica. in costa rica, he grows coffee. my brother lives in a place-- scout's honor. he lives in a place where there's no electricity. that what he wills. he's living his childhood fantasy. he's way, way out in the back hills there, lives in a little franca, a little farm there and he grows coffee. and the last time i'm visiting my brother, he happened to mention to me that they have to import sweet corn. i said, "why you gotta be importing sweet corn?" he says, "we don't have enough sun." "you don't have enough sun? "you got mangoes up the backyard there. "you got guava trees. you got tangerines. "you got grapefruit. "what do you mean you don't have enough sun? you got plenty of sun." he says, "no, brother. no, brother. not enough hours of sun." "ah, hours of sun." costa rica, like hawaii, about 12-hour days, 12-hour nights all year round, isn't that true? we don't have a period when we have long, long days and short, short nights and vice versa.

we don't get that here in hawaii because you're at the equator, and that's just about half, half no matter where you go. it's only when you get through the pole you get the extremes. it's only up here where someone is on nighttime all day long, okay? and then six months later, be in the daytime all day long, okay? it's only up here. down on here, it's pretty well even all year round. so i thought that was kind of interesting. yeah. on the matter of saying that the closer one to the equator is the warmer one, that's like taking a couple of pieces of paper and holding them out in the raiain. let's suppose i hold these two papers in a rain like this and they get wet, yeah? and a friend comes by and i take it back in. and the friend looks at the papers and the friend says, "hey, geewhiz, this paper is wetter than this one. hc?" i said, "well, i don't know. let me show you." then i go like this. can you see why this wetter get-- this piece of paper get wetter? yeah. and the friend say, "oh, i see why, "because this piece of paper is closer to the clouds." [laughter] true? it is closer to the clouds, but that's not the reason. it has to do with the tilt, doesn't it?

and does that tilt have anything to do with the seasons of the world? does it? think about that. you know why i want you to think about that? 'cause its physics. hey. all right. go. [music] captioning performed by aegis rapidtext

you are bonkers 'cause iron doesn't float. people make boats out of wood. well, here's this clay, and it has the same weight. watch this. oh, yuck. [laughter] yucko. yeah, we got it now, gang. isn't that nice? now it's being held up by what? your fingers. my fingers. you get the idea. concentration of force is pressure. so let's talk about that, gang. pressure, definition.

screwed up. i don't wanna talk about pressure. i wanna talk about density first. you guys, can you come in on wednesday? [laughter] how do we find the center of gravity of different things? well, the book's easy. how about something like this? there's a way. and the way is very easy. let me show you. all i gotta do is suspend it. suspend it by that point. guess where the center of gravity is, gang? it's somewhere beneath this line, okay? over here, somewhere in here. now, let me try this again, gang. troy, i think our board is insufficient. let me try this again. let me hold it from here, gang.

the center of gravity is somewhere along there. and i can see if that's true by seeing if it will balance. and it does. so it's somewhere along there-- where along there? i can hang it by another point and find out that it's-- now, troy, the center of gravity of this board is within the board. that blows everything, gang. i don't know what to do. yeah, the board's too fat. look at the globe here.

in the summertime, amsterdam is way up here, okay? now, let's suppose we have an imaginary line right in here about where darkness is, okay? everything to this side here is dark, 'cause let's suppose the sun is coming in this way, okay? sunlight is coming in. well, let's look at amsterdam way up here. yeah, right here, okay? first of all, the sun comes up. here they are. day, day, day, day, day, day, day, day, day, day, day, day, day, day, day, day, night, night, night, night, night, night, night, day, day, day, day, day, day. most of the time, they're in the sunlight. the sun come right here. most--i've got this wrong. i've got this wrong, gang. i've been doing it. in fact, when i get over here and started halfway, what? did you see i screwed up? i screwed up. what was my screw up? check the neighbor and see how hewitt screwed up. [laughter] how did hewitt screw up? come on, check the neighbor.

how many are saying, "it looked all right to me." [laughter] come on. how did i screw up? you actually turned it over. yeah. turned it over. well, you gotta- well, for television-- okay, it's got 24 times as much area to feed itself. but what's wrong with that, gang? twenty-four times as much area is feeding how much more cell? 1, 2, 3, 4, 5, 6, 7, 8, eight times. oops. that was 24. yeah, it mixed up. yeah, eight times much. four times. oh, now, i mixed up, gang. i'm getting mixed up. it is four times as much total area, because 24 is four times six. four times six, that's why i screwed up. what i'm gonna do? what i'm gonna do? how do we start that? thanks for bailing me out again, lee. what are we talking about--

i'm self-conscious when this camera is on me. the cell is getting bigger and bigger. huh? the cell is getting bigger and bigger. oh, yeah. [laughter] you guys get freaked out with this thing looking at you -how about me, yeah? [laughter] the living cell gets bigger and bigger, right? let's suppose the living cell gets double the size. slight, uh-huh-- what do we got here, gang? [laughter] what do we got here? trouble. i've got a tablecloth. i've got a tablecloth with no lip, okay? - no. - watch this. those dishes are essentially at rest, aren't they? here's something for you to do this weekend when you finally get invited to your friend's house for dinner, okay? and the friend wants to know, what are you doing, what are you doing at school? you can kind of show him this, right? you don't wanna try this at your own house, not with your own dishes, okay? you might mess--but you try them at your friend's house. how about this, gang? what's gonna happen if i pull this thing very, very quickly, huh? what's gonna happen? -- let's try it. a one, a two, a three.

and there you see newton's law flawlessly executed. that distinction between-- that distinction between weight and mass, i can kind of show you that kind of neatly with this device. what i'm gonna do is take this heavy ball-- heavy ball or massive ball? - both. - yes. both, yeah. see, i'm gonna take this ball. it's got a lot of mass, also has a lot of weight, okay? and what i'm gonna do, i'm gonna take one of these strings in the bottom. you see i'll try different trials here. and i'm gonna pull, pull, pull. i'm gonna pull, pull, pull, pull, pull, pull, until one of these strings, either the bottom one or the top one, is gonna break. and what i want you to do is i want you to guess, hypothesize, which string, the top or the bottom will break with a gradual, gradual tension

increased at the bottom? check your neighbor. okay, when i pull that very, very slowly, gang, which string gonna break, top or bottom? - top. - top. top one? how many say the top? let's try it. [laughter] maybe newton's having a bad day. [laughter] you know what that might have been? that might have been a string before that we partially damaged. yeah. probably. can we start the tape... but with an angle like that, doesn't it travel a greater distance than the one that's just falling vertically? so for them to hit the same time, it has to be going faster. the object has to be traveling faster. it turns out, if i jump off the lanai like this, i'll step off like this. i'll step off like that. i'll hit at the same time in all places. over here, i'll be going faster, because i have a bigger speed like this.

and that arrow is gonna be bigger than this and this. i'd be faster, but i've gone a further distance. - right. - okay. and later on we'll talk about a neat, neat concept that'll tell you that down here, the--wait a minute, i will not be going faster. erase the tape. lionel, that's wrong. it turns i'll have the same speed here, here and here. no, i won't either. no, i won't either. now, lionel, the tape's okay. leave it going. sorry. [laughter] i get a little mixed up. do you guys get mixed up with this stuff? i mean, all the time, i get mixed up with elementary physics. so if you guys get mixed up, don't feel bad. i'm with you, all right? with this clip, i'm gonna fasten the point to here. now, i'm gonna crank this again, okay? if you see a lightning bolt from here to here, if you see that, scouts honor, "a" in the course. if you don't see that, then you got to do your exams

and study and da, da, da, da, okay? so let's try it now. [laughter] i've seen it. scouts honor. scouts honor. never go back on a scout's honor. [laughter] oh, boy. [laughter] it's almost as if there's a spark there, isn't there? [laughter] this is most unusual. i think i see-- try switching the other side. no. and, gang, i have no explanation for this. this is new to me. can you put it on the other side? this should--it should be less probable, though, but--

you see it's got to leak from one to the other. i wonder if it's because i didn't discharge it to begin with. let me try something. --continuing to charge. isn't that in a way-- yeah, it does. it turns out it does, yeah. but i could--you crank it counter clockwise. okay, watch this now. it shouldn't do. [laughter] that blows me out. that blows me out. this has never happened before. i've never noticed-- and if the leak's off that point, then it should drift over here without having that snap, snap, snap, and it's not happening. try to--when you put the two points on it, you turn it the other the way. oh, well, i didn't mean to do that, but... see if it works-- now, but that-- maybe you should discharge it first. [laughter] oh my god. [laughter]

i noticed everyone out there seems to be pretty happy today. [laughter] you seem to be pretty happy because you see the old fool up here making a damned fool of himself, right? you guys should all be saying, "oh, gee--so we could-- "yeah, we can test to see whether things are *true. "if i bring a positive--i bring a positive object nearby, "shouldn't the positive object attract the negatives and pull the negatives from there? mm-hmm. and shouldn't the leads collapse? one of the nice things about science is you start to understand and see if you can predict things. and if you can, then it tells you that your theory probably is more likely correct than more likely wrong. let's try that, gang. if this is more positive-- oh my god. [laughter] why does it still diverge more? that blows me away, gang. is that coming together?

it's getting more and more diversion. and it should collapse when i bring this over. it should. what do you mean it should? it's doing what it should. my explanation is just off, right? [laughter] look at that. i've got nothing to-- i'm supposed to be teaching you guys electrostatics. i've got nothing to say. in fact, probably everything i say is just all canned crap. [laughter] because, honey, it's just not doing. look at that. i've got nothing to say. i could talk about coulomb's law a little bit, but i don't believe in it anymore. [laughter] let's continue as if everything were going smooth. it's called make believe. i thought science was all about making discoveries, experimental and-- we could continue with this, couldn't we? we could continue and maybe find something fundamental,

but it's not part of my act. [laughter] well, okay, let's move on, gang. i don't know. someone's gonna give me an explanation of what's happening here. and i'm gonna be very impressed. who is going to be the one? in fact, that could be like a term project. what went wrong tonight? who's gonna say, "hewitt, nothing went wrong at all. "what happened was, da, da, da, da, da, da, da. "what went wrong was your failure "to be able to observe and interpret what happened to it. da, da, da, da, da. nature is not wrong, you is." okay? someone write it out, 'cause i am baffled, gang. [music]

paul hewitt here, a few words. you know who we are and what we're about has a lot to do with the influences in our life, the people who have influenced us. and i, like everyone, have had many, many influences.

and i just wanna cite, oh, very few, just three or four here. i know when i was in high school, there was a counselor, edward gibbs, high school counselor, and he advised me to not take any academic subjects because i wouldn't need to, because he was aware of my talent for art. i was the guy that would paint the posters for the dances, make the cartoons in the yearbook and that kind of thing. and so he said i wouldn't have to take academic courses, so i took his advice and i didn't. and so in high school, i took no physics, no science. i did mathematics for boys in the freshman year, and there was a general science course and i thought it was wonderful. but that's about it for that. and another one of my influences was kenny isaacs. kenny isaacs was a local boxing hero. and i was one of these kids that was getting beat up all the time by bullies. i wasn't much of a physical specimen.

and kenny isaacs was-- he was the fighter of fighters. everyone admired that guy. i remember going to lynn and watching him fight sometimes. i was about maybe 14 years old, 13, 14, and saying, "wow, this guy is so great." i wish i could be there in his corner, be sort of the kid that comes up with the water bucket, you know, and helps him. this is a gladiator, no one beat him up. but anyway, kenny isaacs was a big influence because, to make a long story short, three years later, kenny isaacs was in my corner. and a fellow lived next door to me, eddie mccarthy, who was a professional fighter, 135-pound, lightweight, very good guy. and he took me under his wing. but then he went off to the korean war. just before he did that, he turned me over to a local boxing hero, kenny isaacs. and he told kenny, "kenny, take young paul here under your wing. he's my protege." kenny did that. and i was gonna retire as soon as i won the flyweight championship of north america, but i never got that far.

i got up to the silver medal for the aau in new england at the age of 17. and that was about it. after that, in the follow-up fight, getting ready for the nationals, i got knocked out, the end of that career. another big influence on my life was burl grey, a sign painter that i met back in the late fifties. burl was painting in miami and i was assigned to paint with him. no one else would paint with him because there was a rumor going around about him that he was, yeah, one of them. he was accused of being, and i found out for myself that old burl was an intellectual. and intellectuals didn't cut it at the sign painting circuit. anyway, burl grey influenced me a lot. he's the one that lit my fire to get into science. and many of the ideas i had about things were-- burl sort of demolished. he was a very philosophical type and he was a nontheist.

and he, you know, convinced me that things were so much simpler if you took a more scientific view of the world and there's so much that we're taught to believe or that we come to believe that simply isn't true. and how does one determine what's true or not? do you find out when you're an old person ready to die that everything you've been doing is just junk? well, you know, we each need a knowledge filter, sort of, to tell the difference between what's true and what isn't true. and burl convinced me that the best knowledge filter ever invented is science. and so i got into science. i went to school. i went to college, lowell tech in massachusetts, after doing a year of prep school 'cause i didn't take the recommended courses in high school, i had to do this, you know, make up for deficiencies. so burl was a big influence of mine. and then i went through it and i got a physics degree. and while getting that physics degree, it was very, very difficult for me. but there was a book i read when i was in graduate school in the summertime.

it was wonderful. it was a book called "basic physics" by ken ford. and ken ford became my mentor and another big influence on me. and ken ford's book, awesome. he told it like it is. ken ford is a giant himself. he doesn't have a nobel prize but his friends do. he's one of those type guys. he was the exec officer of the american institute of physics. i'm proud to say now, i'm very proud of him to have him for a personal friend. so he was a great influence on me. and now i find myself, my greatest satisfaction is to realize that i myself am an influence for other people. i'm sort of a kenny isaacs or a burl grey or a ken ford to many students. and this many is with a capital m, thanks to the efforts of my friend marshall alenstein who has put together these videotapes and these dvds that spread my lectures from the classroom into the classrooms of many people.

and so, it's wonderful being that role model for other teachers and students. and whatever i can do to be a burl grey to other people, to let them see that perhaps a very good foundation for, hey, what's going on in the world, certainly, is science. so let's hear it for physics. physics first, it's a wonderful way to look at the world. it makes sense out of what ordinarily might be just too cplex to understand. physics, i love it. i hope you do too.